The physical layer of some wireless communication systems using forward error correction (FEC) coding must be able to transmit a wide variety of packet sizes. In order to bound the memory usage of the FEC decoder in such systems, it is known to break up or “segment” larger information packets into smaller “code block segments”, which are encoded independently. When segmentation is used, there is a need for rules that determine the number of physical channel resources to assign to each code block segment. These rules are referred to here as “physical channel segmentation” rules.
In the High Speed Packet Access (HSPA) extension of the 3GPP Universal Mobile Telecommunications System (UMTS) protocol, the physical channel segmentation rule is applied after a step of concatenating all of the encoded code block segments. Therefore, the segmented physical channel resources are not directly identifiable with code block segments. This adversely affects the ability to pipeline the channel equalization and channel decoding in the receiver.
In the WiMAX protocol, the segmented physical channel resources are directly identifiable with code block segments. However, in WiMAX, the physical channel resources can be segmented to a granularity of 48 modulation symbols, and all code block segments must have exactly the same code rate. In systems like the developing Long Term Evolution (LTE) of the 3GPP UMTS protocol where the available physical channel resources change from frame-to-frame, a much more flexible solution with a finer granularity of segmented physical channel resources is required.
The various aspects, features and advantages of the present disclosure will become more fully apparent to those having ordinary skill in the art upon careful consideration of the following Detailed Description thereof with the accompanying drawings described below. The drawings may have been simplified for clarity and are not necessarily drawn to scale.